As the industrial machine, for example, a hydraulic excavator has a lower travel base and a revolving upperstructure which is revolvably coupled to the lower travel base. The revolving upperstructure is equipped with a front working mechanism as a working mechanism. The front working mechanism has a boom and an arm. The boom is mounted to the revolving upperstructure in such a manner as to be raised/lowered. The arm is vertically rotatably coupled to the distal end of the boom. The distal end of the arm is equipped with a front attachment. The front attachment is a bucket when used in excavation work.
It is well known in the art to provide a surround monitoring device to monitor the surrounding circumstances of the revolving upperstructure in order to ensure work safety while the front working mechanism serving as the working mechanism is driven to carry out earth/soil excavation work and/or the like. The surround monitoring device is configured to include a camera mounted to the revolving upperstructure, and a monitor placed, within a cab, in front of the operator seat in which the operator is to sit. Images taken by the camera are displayed on the monitor screen in the form of moving images. Also, ensuring the safety during traveling of the hydraulic excavator and during excavation work or the like, and the like, requires the field of view covering the rear and both the left and right sides of the revolving upperstructure. In order to provide a wide-angle field of view around the hydraulic excavator which is the industrial machinery, the revolving upperstructure equipped with a plurality of cameras is conventionally used. This eliminates blind spots from almost all around the revolving upperstructure, ensuring the work safety and improving the maneuverability of the industrial machine.
Patent Literature 1 discloses the configuration in which view transformation processing is applied to images of the surroundings of the industrial machine captured by a plurality of cameras for a view from above so that the images are displayed as two-dimensionally-projected top-view monitoring images on the monitor screen. With the configuration in Patent Literature 1, the plurality of cameras are mounted to the revolving upperstructure of the hydraulic excavator and the images of the respective cameras are combined on the monitor screen in order to obtain the surround monitoring image.
The cameras are mounted in three locations, in a position in a rear portion of and positions in the right and left side portions of the hydraulic excavator, in which the optical axis of the imaging lens of each of the cameras is directed in an obliquely downward direction. An image taken by each camera is a through image, so that the view transformation processing is applied to the through image to obtain a monitoring image. The view after the transformation is a view from above, thereby obtaining the three top-view images projected from above the hydraulic excavator.
With this configuration, the top-view images are displayed on the monitor screen, in which an image illustration symbolically showing the hydraulic excavator (specifically, a plane image illustration of the hydraulic excavator) is displayed on the monitor screen and the top-view images captured by the respective cameras are arranged around the image illustration. More specifically, the image illustration is displayed on a central position of the monitor screen and the top-view images are arranged respectively in regions on the rear side and the left and right sides of the image illustration, resulting in displaying the bird's-eye view image for surround monitoring.